NI number for SFE

Hi,

I been trying to put my NI number in for my SFE as my application has been approved and all that needs to be done is for me to give my NI. However, the system says I have used this number before for another application (which I have not as I got the number this week) and every time I try to upload evidence it leads me to a page where I can't press the button to upload. Any tips?